Hafnium oxide and aluminium oxide alloyed dielectric layer and method for fabricating the same

• US 20050110069A1
• Filed: 04/07/2004
• Published: 05/26/2005
• Est. Priority Date: 11/22/2003
• Status: Abandoned Application

• Current Assignee: Hynix Semiconductor Incorporated (SK Hynix Inc.)
• Original Assignee: Hynix Semiconductor Incorporated (SK Hynix Inc.)
• Inventors: Kil, Deok-Sin, Roh, Jae-Sung, Sohn, Hyun-Chul
• Application Number:
  US10/819,202
• Publication Number:
  US 20050110069A1
• Time in Patent Office: Days
• US Class Current: 257/306
• CPC Class Codes: C23C 16/40 Oxides
• CPC Class Codes: C23C 16/45529 specially adapted for making a layer stack of alternating different compositions or gradient compositions
• CPC Class Codes: C23C 16/45531 specially adapted for making ternary or higher compositions
• CPC Class Codes: H01L 21/02178 the material containing aluminium, e.g. Al2O3
• CPC Class Codes: H01L 21/02181 the material containing hafnium, e.g. HfO2
• CPC Class Codes: H01L 21/02194 the material containing more than one metal element
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD
• CPC Class Codes: H01L 21/3142 of nano-laminates, e.g. alternating layers of Al203-Hf02
• CPC Class Codes: H01L 21/31616 Deposition of Al2O3
• CPC Class Codes: H01L 21/31645 Deposition of Hafnium oxides, e.g. HfO2
• CPC Class Codes: H10B 12/05 Making the transistor

Abstract

The present invention relates to a dielectric layer alloyed with hafnium oxide and aluminum oxide and a method for fabricating the same. At this time, the dielectric layer is deposited by an atomic layer deposition technique. The method for fabricating the hafnium oxide and aluminum oxide alloyed dielectric layer includes the steps of: depositing a single atomic layer of hafnium oxide by repeatedly performing a first cycle of an atomic layer deposition technique; depositing a single atomic layer of aluminum oxide by repeatedly performing a second cycle of the atomic layer deposition technique; and depositing a dielectric layer alloyed with the single atomic layer of hafnium oxide and the single atomic layer of aluminum oxide by repeatedly performing a third cycle including the admixed first and second cycles.

Claims

1. A dielectric layer of a semiconductor device, comprising a hafnium oxide and aluminum oxide alloyed dielectric layer through the use of an atomic layer deposition technique.

2. The dielectric layer as recited in claim 1, wherein the hafnium oxide and the aluminum oxide are HfO₂ and Al₂O₃, respectively and the hafnium oxide and aluminum oxide alloyed dielectric layer has a molecular structure of (HfO₂)_1-x(Al₂O₃)_x, in which x represents a molecular composition ratio.

3. The dielectric layer as recited in claim 2, wherein each of the HfO₂ layer and the Al₂O₃ layer has a thickness ranging from about 1 Å

to about 10 Å

.

4. The dielectric layer as recited in claim 2, wherein in the molecular structure of (HfO₂)_1-x(Al₂O₃)_x, the subscript x representing a molecular composition ratio of the Al₂O₃ layer ranges from about 0.3 to about 0.6.

5. A method for fabricating a dielectric layer of a semiconductor device, comprising the steps of:

depositing a single atomic layer of hafnium oxide by repeatedly performing a first cycle of an atomic layer deposition technique;

depositing a single atomic layer of aluminum oxide by repeatedly performing a second cycle of the atomic layer deposition technique; and

depositing a dielectric layer alloyed with the single atomic layer of hafnium oxide and the single atomic layer of aluminum oxide by repeatedly performing a third cycle including the mixed first and second cycles.

6. The method as recited in claim 5, wherein the single atomic layer of hafnium oxide and the single atomic layer of aluminum oxide are an HfO₂ layer and an Al₂O₃ layer, respectively and the hafnium oxide and aluminum oxide alloyed dielectric layer has a molecular structure of (HfO₂)_1-x(Al₂O₃)_x, in which x represents a molecular composition ratio.

7. The method as recited in claim 6, wherein each of the HfO₂ layer and the Al₂O₃ layer has a thickness ranging from about 1 Å

to about 10 Å

.

8. The method as recited in claim 6, wherein a ratio of the first cycle and the second cycle is controlled to make the subscript x representing the molecular ratio of the Al₂O₃ layer range from about 0.3 to about 0.6.

9. The method as recited in claim 5, wherein the first cycle is a unit cycle constituted with sequential steps of providing a source gas of hafnium, a purge gas, an oxidation agent and a purge gas.

10. The method as recited in claim 6, wherein the first cycle is a unit cycle constituted with sequential steps of providing a source gas of hafnium, a purge gas, an oxidation agent and a purge gas.

11. The method as recited in claim 9, wherein the source gas of hafnium is selected from a group consisting of HfCl₄, Hf (NO₃)₄, Hf (NCH₃C₂H₅)₄, Hf[N(CH₃)₂]₄ and Hf[N(C₂H₅)₂]₄;

the oxidation agent is one of O₃ and H₂O and O₂ plasma; and

the purge gas is one of N₂ and Ar.

12. The method as recited in claim 10, wherein the source gas of hafnium is selected from a group consisting of HfCl₄, Hf(NO₃)₄, Hf(NCH₃C₂H₅)₄, Hf[N(CH₃)₂]₄ and Hf[N(C₂H₅)₂]₄;

the oxidation agent is one of O₃ and H₂O and O₂ plasma; and

the purge gas is one of N₂ and Ar.

13. The method as recited in claim 5, wherein the second cycle is a unit cycle constituted with sequential steps of providing a source gas of aluminum, a purge gas, an oxidation agent, and a purge gas.

14. The method as recited in claim 6, wherein the second cycle is a unit cycle constituted with sequential steps of providing a source gas of aluminum, a purge gas, an oxidation agent, and a purge gas.

15. The method as recited in claim 13, wherein the source gas of aluminum is one of trimethylaluminum (TMA) and modified TMA (MTMA);

the oxidation agent is one of O₃ and H₂O and O₂ plasma; and

the purge gas is one of N₂ and Ar.

16. The method as recited in claim 14, wherein the source gas of aluminum is one of TMA and MTMA;

the oxidation agent is one of O₃ and H₂O and O₂ plasma; and

the purge gas is one of N₂ and Ar.

17. A method for fabricating a dielectric layer alloyed with hafnium oxide and aluminum oxide, the method comprising the step of repeatedly performing a unit cycle of sequentially providing a single molecular source gas of hafnium and aluminum, a purging gas, an oxidation agent, and a purge gas.

18. The method as recited in claim 17, wherein nomenclatures of the hafnium oxide and the aluminum oxide are HfO₂ and Al₂O₃, respectively and the hafnium oxide and aluminum oxide alloyed dielectric layer has a molecular structure of (HfO₂)_1-x(Al₂O₃)_x, in which x represents a molecular composition ratio.

19. The method as recited in claim 17, wherein the single molecular source gas of hafnium and aluminum is HfAl(MMP)₂(OiPr)₅;

the oxidation agent is one of O₃ and H₂O and O₂ plasma; and

the purge gas is one of N₂ and Ar.